Understanding Continuity and Intervals for Limits in Functions

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Discussion Overview

The discussion centers around understanding the concept of continuity in relation to limits, specifically for the function f(x) = 1/x^3. Participants are exploring how to determine the intervals where this function is continuous and the underlying principles of limits and continuity.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Homework-related

Main Points Raised

  • One participant expresses confusion about limits and continuity, seeking clarification on how to determine the intervals of continuity for f(x) = 1/x^3.
  • Another participant states that a function is continuous when the limit as h approaches 0 of [f(x+h) - f(x)] equals 0, and notes that the composition of continuous functions is also continuous.
  • There is a reiteration of the continuity of x^3 and a question about where 1/x is continuous.
  • A suggestion is made to express f(x) as a composition of functions, indicating that f is continuous at a point if and only if 1/x is continuous at that point, prompting a discussion about the domain of 1/x.
  • Participants emphasize that a function cannot be continuous where it is undefined, specifically referencing the domain of 1/x.

Areas of Agreement / Disagreement

Participants generally agree on the principles of continuity and the need to consider where functions are defined. However, there is no consensus on the specific intervals of continuity for f(x) = 1/x^3, as this remains unresolved.

Contextual Notes

Limitations include the lack of explicit definitions for continuity in this context and the unresolved mathematical steps regarding the determination of intervals for continuity.

noobie!
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i would like someone to clear my doubts by explaining how it actually works..limits is one of the chapter i fear about it cause I am quite blur with it..so i do need someone help me;v this que..given f(x)=1/x^3 what r the intervals for function continuous ?how to solve it?thanks :)
 
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f is continuous when
lim_{h->0} [f(x+h)-f(x)]=0
also composition of continuous funtions are continuous
x^3 is everywhere continuous
where is 1/x continuous?
 
lurflurf said:
f is continuous when
lim_{h->0} [f(x+h)-f(x)]=0
also composition of continuous funtions are continuous
x^3 is everywhere continuous
where is 1/x continuous?

u meant composite of continuous function could also be a continuous for x^3?bt the limit is not given?!so what will be the interval for the function?how to differentiate between them and i still don't really get your point;i'm so sorry!
 
let g(x)=x^3
write f(x)=1/x^3
as
f(g(x))=g(1/x)=(1/x)^3
g(x) is continuous for all real numbers (show this)
so f is continuous at a if and only if 1/x is continuous at a.
Where is 1/x continous?

Start by giving the domain of 1/x
A function cannot be continuous where it is undefined.
 
lurflurf said:
let g(x)=x^3
write f(x)=1/x^3
as
f(g(x))=g(1/x)=(1/x)^3
g(x) is continuous for all real numbers (show this)
so f is continuous at a if and only if 1/x is continuous at a.
Where is 1/x continous?

Start by giving the domain of 1/x
A function cannot be continuous where it is undefined.

hmm,then i think i get your point..anyway thanks a lot...:smile:
 

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